Patent · US Expired

Telephone summing circuit

US4230908A · kind A · utility

9Cited by
3References
15Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJan 22, 1979
Grant dateOct 28, 1980
Priority date
Expiry dateJan 22, 1999

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04M3/568
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

The addition of two digitized audio signals, each of which has been non-linearly compressed and PCM encoded, is accomplished by converting only one of the signal samples (preferably the smaller) to an exponential-format value which may be linearly added to the other.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.